1. Field of the Invention
The present invention relates to a disc device for driving optical discs (such as CD-R/RW and DVD-R/-RW/RAM/+R/+RW) as a recording medium for recording a large amount of information in information processing apparatuses such as various computer systems.
2. Description of the Related Art
Generally, disc devices built into personal computers (hereinafter, referred to as PCs) comprise disc trays for loading discs, such that the disc trays proceed into and retract from the disk devices. The discs placed on the disc trays are driven in the main bodies of the disc devices to record information or to reproduce information.
On the other hand, disc devices having a slot (not being implemented with the disk trays) are also widely used to make the PCs thinner and smaller. According to this type of disc devices, since the disc trays are not used when the discs are loaded in or unloaded from the main bodies of the disc devices, when an operator inserts a disc by half or more into a slot, the loading mechanism of the main body operate such that the disc is automatically loaded.
FIGS. 46 and 47 illustrate the structure and the operation of a loading mechanism in a conventional disc device implemented with a slot-in method. According to the structure illustrated in FIGS. 46 and 47, when an operator inserts a disc D, the vertical and horizontal positions of the disc D are controlled by a pin 100a at the tip of a first pivoting body 100, right and left guide bodies 101 and 102, and a pin 103a at the tip of a second pivoting body 103 in the middle of the process, such that the disc D reaches the position illustrated in FIG. 46.
At this time, the pin 100a at the tip of the first pivoting body 100 is pressed by the disc D, such that the first pivoting body 100 pivots in the direction marked with an arrow 100A. Also, the pin 103a at the tip of the second pivoting body 103 is pressed by the disc D, such that the second pivoting body 103 pivots in the direction marked with an arrow 103A. A switch lever 104 is pressed by the end of the second pivoting body 103, such that the switch lever 104 pivots in a direction marked with an arrow 104A to operate a detection switch 105.
When the detection switch 105 operates, driving means 106 is driven, such that a first slide member 107 starts to move in the direction marked with an arrow 107A. Since the tips of the first slide member 107 and a second slide member 108 are connected to each other by a slide connecting member 109 that is supported by a pin 110 to pivot, the second slide member 108 proceeds in the direction marked with an arrow 108A in synchronization with the recession of the first slide member 107.
Accordingly, when the first slide member 107 starts to retract, since a driven pin 100b of the first pivoting body 100 supported to the slide member 107 in a cantilever state is guided in a cam groove 107a of the first slide member 107, the pivoting body 100 rotates in the direction marked with an arrow 100B around a support point 100c. Accordingly, the pin 100a at the tip of the first pivoting body 100 returns the disc D in the direction marked with the arrow 107A until the disc D abuts on pins 111a and 111b of a disc position determining member 111.
At this time, since the pin 103a of the second pivoting body 103 pivots in the direction marked with the arrow 103A, the pin 103a of the second pivoting body 103 moves in the direction marked with the arrow 103A while supporting the disc D in synchronization with the pin 100a located at the tip of the first pivoting body 100 and rotates to the position slightly remote from the disc D after the disc D abuts on the pins 111a and 111b of the disc position determining member 111.
The loading mechanism operates as mentioned above when the disc D is loaded in the device and operates in reverse to the above when the disc D is unloaded to the outside of the device. That is, as illustrated in FIG. 47, in the case where the disc D is in a prescribed position in the device, when the driving means 106 is driven in a reverse direction in accordance with an unload command, the first slide member 107 starts to proceed in the direction marked with an arrow 107B, and the second slide member 108 connected to the slide connecting member 109 starts to retract in the direction marked with an arrow 108B in synchronization with the procession of the first slide member 107. Accordingly, since the first pivoting body 100 pivots in the direction marked with the arrow 100A and the second pivoting body 103 pivots in the direction marked with the arrow 103B, the disc D is supported by the pins 100a and 103a at the tips of the first pivoting body 100 and the second pivoting body 103 and is unloaded to the outside of the device.
Also, the disc D loaded in the device is clamped by a clamp head 112 that is in an up and down motion in the exact position. The clamp head 112 is integrated with a turntable 113 fixed to the driving shaft of spindle motor 114 that is arranged in a frame 115, such that the frame 115 is movable in vertical direction by an ascending and descending mechanism.
When the disc D is unloaded, since the pivoting body 103 is unlocked from the driving means 106, such that the pivoting body 103 operates independent of the driving means 106, the pivoting body 103 pivots in the direction marked with the arrow 103B by the elastic supporting force of a spring to unload the disc D. Thus, since the elastic force of the spring is the only the driving force for unloading the disc D, the halting position of the disc D unloaded to the outside of the device is not always constant and the disc D is often unloaded to the outside of the device while rotating (for example, the patent document 1).
[Patent Document 1]
Gazette of Japanese Unexamined Patent Application Publication No. 2002-117604
According to the disc device having the above-mentioned structure, in order to make the first pivoting body 100 and the second pivoting body 103 operate in a cooperative manner, the first slide member 107 and the second slide member 108 are connected to each other by the slide connecting member 109, such that the second slide member 108 proceeds in synchronization with the recession of the first slide member 107. When the disc D is unloaded to the outside of the device, the force toward the direction marked with the arrow 103B of the second pivoting body 103 is mainly applied.
In the state when the disc D is unloaded to the outside of the device, that is, in the state when the disc D is in the position illustrated by an imaginary line and the second pivoting body 103 rotates in the direction marked with the arrow 103B as illustrated in FIG. 46, and when the disc D is pushed in the direction where the disc D is loaded and returns, the force in a negative direction is generated against force in a positive direction, which normally operates, such that the entire loading mechanism is in the reverse motion to damage the respective portions and the driving means 106.
In the state when the disc D is loaded in the device, that is, in the state when the disc D is in the position illustrated by an imaginary line and the first pivoting body 100 pivots in the direction marked with the arrow 108B as illustrated in FIG. 46, and when the disc D is pulled in the direction where the disc D is unloaded and returns, the entire loading mechanism is in the reverse motion to damage the respective portions and the driving means 106.
Such a problem is mainly caused by careless handling of the disc D by an operator, and it is required for the operator to carefully handle the disc D. In the case when the operator poorly handles information processing apparatuses such as a PC or when the operator desires to stop the unloading of the disc in the middle of the process, undesirable load may be applied to the loading mechanism when the operator instinctively returns the disc exposed to the outside of the device or when part of the body of the operator happens to touch the disc unloaded and exposed to the outside of the device to damage the loading mechanism. Also, when the disc is loaded in the main body of the device, when the operator stops the loading of the disc in the middle of the process, the operator may instinctively grab the end of the disc that is being loaded in the main body or pull the end of the disc to retrieve the disc from the device.
When such operations are performed, according to the above-mentioned loading mechanism in a conventional disc device being implemented with a slot-in method, since the pivoting body in the portion that loads and unloads the disc is in a cantilever state, even if a slight amount of force is applied to the tip of the portion that loads and unloads the disc, strong angular moment is generated at the end, such that the force in the negative direction, which is more than ten times the force required for unloading the disc, may be generated to easily damage the loading mechanism. Thus, in order to solve such a problem, as means for protecting the loading mechanism from abnormal operations, it was tried to improve the strength of the loading mechanism, to optimize the output of the driving portion, and to detect the load. However, it is still difficult to overcome the above problem in spite of the increased manufacturing cost, complicating of the loading mechanism, and increasing the weight.